We previously reported the age-specific incidence rate for idiopathic Parkinson's disease (IPD) among women and Black Americans to be equal, and in some instances higher, than that among men and Whites. In contrast, the age-specific prevalence was significantly lower for women than men and lower for Blacks than Whites, consistent with the prevailing observations. The lower prevalence in this community study was, in part, explained by the observation that mortality for Blacks with IPD was 3 times that for Whites, but this did not explain the lower prevalence among women compared with men. Using a combination of data resources available to us, we will address a series of hypotheses related to gender and ethnic differences in the prevalence, morbidity and mortality associated with IPD. This investigation capitalizes on the four ferally supported projects in place providing data on nearly 900 patients with IPD and similar data on 1800 individuals from the same geographic region without IPD. First, we will investigate ethnic and gender differences in disability and death, expand data gathering on co-existing health conditions, institute an annual follow-up program to capture several physical and cognitive measures that are currently measured at baseline and obtain death certificates for all decedents. We will use a disease risk classification scheme for all co-morbid and associated conditions including dementia, atherosclerotic disease and stroke. Using the additional follow-up data specifically collected for this project, ethnic and gender differences in total life expectancy (TLE) and active life expectancy (ALE) will be compared for those with and without IPD and among those with IPD to calculate years of life or active life lost due to the illness. Secondly, we will use our data and existing secondary databases containing clinical, survey, and death certificate information to complete a validity analysis between administrative and clinical data sources, characterizing and quantifying factors and bias associated with ethnic differences in the recording of Parkinson's disease on death certificates. The clinical relevance of the latter is related to the belief that Blacks and women are at significantly lower risk from Parkinson's disease-a concept, whose strongest support lies in numerous large studies of death certificate.